Kurzweil's money does not materialize out of thin air.
I don't know if he is rich enough to sustain himself, but he is certainly not giving away his futurism books, his longevity supplements, or his lecture talks for free. The people paying for Kurzweil's products and services also have to believe in his statements and predictions, and that Kurzweil is the one who deserves their money.
If I were to single out one of these two parties for having a greater financial incentive in the perpetuation of their ideas, my money would be on the businessman/entrepreneur, not on the research fellow working for a charity.
I just watched Transcendent Man about the singularity and Ray Kurzweil in particular. It's well-made, full-length, and includes the most popular criticisms of Kurzweil: that his prediction timeframes are driven by his own hope for immortality, that the timescale of his other predictions are too optimistic, that his predictions about the social outcomes of revolutionary technology are naively optimistic, and so on. Ben Goertzel and others get much face time.
You can rent or buy it on iTunes.